/* ===== 北京知行智研科技有限公司 · 样式 v3（深色 / 侧边栏 / 紫粉） ===== */
:root {
  --bg: #0d1117;
  --panel: #161b22;
  --panel-2: #1c2230;
  --text: #e6edf3;
  --muted: #9aa7b5;
  --line: #232a35;
  --violet: #8B5CF6;
  --pink: #EC4899;
  --grad: linear-gradient(135deg, #8B5CF6, #EC4899);
  --radius: 16px;
  --sidebar-w: 250px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, sans-serif;
  color: var(--text); background: var(--bg); line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }

/* 布局：侧边栏 + 主区 */
.layout { display: flex; min-height: 100vh; }
.sidebar {
  position: fixed; left: 0; top: 0; bottom: 0; width: var(--sidebar-w);
  background: var(--panel); border-right: 1px solid var(--line);
  padding: 30px 22px; display: flex; flex-direction: column; z-index: 40;
}
.brand { display: flex; align-items: center; gap: 12px; margin-bottom: 36px; }
.brand img { width: 44px; height: 44px; }
.brand .name { font-weight: 800; font-size: 16px; color: #fff; line-height: 1.3; }
.brand .name small { display: block; font-size: 10px; color: var(--muted); letter-spacing: 1.5px; }

.side-nav { list-style: none; display: flex; flex-direction: column; gap: 4px; }
.side-nav a {
  display: block; padding: 11px 16px; border-radius: 10px; font-size: 15px; color: var(--muted);
  border-left: 3px solid transparent; transition: .2s;
}
.side-nav a:hover { background: var(--panel-2); color: #fff; }
.side-nav a.active { background: var(--panel-2); color: #fff; border-left-color: var(--violet); font-weight: 700; }

.side-foot { margin-top: auto; font-size: 12px; color: #6b7685; line-height: 1.6; }
.side-foot a { color: #6b7685; text-decoration: underline; text-underline-offset: 3px; }
.side-foot a:hover { color: var(--pink); }
.nav-toggle { display: none; }

.main { margin-left: var(--sidebar-w); flex: 1; min-width: 0; }
.container { max-width: 920px; margin: 0 auto; padding: 0 40px; }

/* Hero */
.hero { position: relative; padding: 96px 0 84px; overflow: hidden; border-bottom: 1px solid var(--line); }
.hero::before { content: ""; position: absolute; width: 420px; height: 420px; right: -120px; top: -160px; border-radius: 50%; background: radial-gradient(circle, rgba(139,92,246,.35), transparent 70%); }
.hero::after { content: ""; position: absolute; width: 360px; height: 360px; left: -120px; bottom: -180px; border-radius: 50%; background: radial-gradient(circle, rgba(236,72,153,.25), transparent 70%); }
.hero .container { position: relative; z-index: 1; }
.hero .logo-big { width: 110px; height: 110px; margin-bottom: 22px; filter: drop-shadow(0 10px 24px rgba(139,92,246,.45)); }
.hero h1 { font-size: 46px; line-height: 1.2; margin-bottom: 16px; }
.hero h1 span { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero p { font-size: 18px; color: var(--muted); max-width: 600px; }
.hero .cta { margin-top: 30px; display: flex; gap: 14px; flex-wrap: wrap; }
.btn { display: inline-block; padding: 12px 28px; border-radius: 999px; font-size: 15px; font-weight: 700; transition: .2s; cursor: pointer; }
.btn-primary { background: var(--grad); color: #fff; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 28px rgba(139,92,246,.45); }
.btn-ghost { border: 1px solid var(--line); color: var(--text); }
.btn-ghost:hover { background: var(--panel-2); }

/* 区块 */
.section { padding: 72px 0; }
.section-title { font-size: 28px; margin-bottom: 8px; }
.section-sub { color: var(--muted); margin-bottom: 36px; }
.eyebrow { display: inline-block; font-size: 12px; letter-spacing: 3px; color: var(--pink); font-weight: 700; margin-bottom: 10px; }

.cards { display: grid; gap: 20px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; transition: .2s; }
.card:hover { border-color: var(--violet); transform: translateY(-4px); }
.card .ico { width: 44px; height: 44px; border-radius: 12px; background: var(--grad); color:#fff; display: grid; place-items: center; margin-bottom: 14px; font-weight: 800; font-size: 18px; }
.card h3 { font-size: 18px; margin-bottom: 8px; }
.card p { color: var(--muted); font-size: 15px; }
.card ul { margin-top: 12px; color: var(--muted); font-size: 14px; padding-left: 18px; }

.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px,1fr)); gap: 16px; }
.stat { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; text-align: center; }
.stat .num { font-size: 32px; font-weight: 800; background: var(--grad); -webkit-background-clip:text; background-clip:text; color: transparent; }
.stat .label { color: var(--muted); font-size: 14px; margin-top: 4px; }

.list { display: grid; gap: 16px; }
.list .item { display: flex; gap: 16px; align-items: flex-start; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px; }
.list .badge { flex: 0 0 auto; width: 44px; height: 44px; border-radius: 12px; background: var(--grad); color:#fff; display: grid; place-items: center; font-weight: 800; }
.list .item h4 { font-size: 17px; margin-bottom: 4px; }
.list .item p { color: var(--muted); font-size: 15px; }

.team-grid { display: grid; gap: 20px; grid-template-columns: repeat(auto-fit, minmax(210px,1fr)); }
.member { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; text-align: center; }
.member .avatar { width: 70px; height: 70px; margin: 0 auto 14px; border-radius: 50%; background: var(--grad); display: grid; place-items: center; color: #fff; font-size: 24px; font-weight: 800; }
.member h4 { font-size: 17px; }
.member .role { color: var(--pink); font-weight: 700; font-size: 14px; margin-bottom: 8px; }
.member p { color: var(--muted); font-size: 14px; }

.contact-grid { display: grid; grid-template-columns: 1.3fr 1fr; gap: 26px; }
.contact-info li { list-style: none; padding: 13px 0; border-bottom: 1px dashed var(--line); display: flex; gap: 12px; }
.contact-info li b { color: #fff; width: 84px; flex: 0 0 auto; }
.contact-info li span { color: var(--muted); }
.map-box { background: var(--panel-2); border: 1px solid var(--line); border-radius: var(--radius); min-height: 220px; display: grid; place-items: center; color: var(--muted); }

/* 页脚（主区底部） */
.footer { border-top: 1px solid var(--line); padding: 30px 0; color: var(--muted); font-size: 13px; }
.footer a { color: var(--muted); text-decoration: underline; text-underline-offset: 3px; }
.footer a:hover { color: var(--pink); }

@media (max-width: 900px) {
  .layout { flex-direction: column; }
  .sidebar { position: static; width: 100%; flex-direction: row; align-items: center; padding: 14px 20px; border-right: 0; border-bottom: 1px solid var(--line); }
  .brand { margin-bottom: 0; }
  .side-nav { flex-direction: row; gap: 2px; margin-left: auto; overflow-x: auto; }
  .side-nav a { border-left: 0; border-bottom: 3px solid transparent; padding: 8px 12px; white-space: nowrap; }
  .side-nav a.active { border-left: 0; border-bottom-color: var(--violet); }
  .side-foot { display: none; }
  .main { margin-left: 0; }
  .container { padding: 0 22px; }
  .hero h1 { font-size: 34px; }
  .contact-grid { grid-template-columns: 1fr; }
}